The bed of pickup trucks is often lined with spray on coatings to protect the metal surface from scratches and to protect the cargo from damage. Additionally, some truck beds are covered with a flexible or ridged cap, or tonneau cover. This cap or cover also protects the cargo from environmental damage and theft.
Pickup truck tailgates, as typically provided by the manufacturers, have no gasket or seal around the perimeter of the tailgate. Lack of a gasket or seal on the tailgate allows dust, rain, and fumes to penetrate into the interior of the pickup truck bed, potentially damaging the cargo and decreasing the protective effect provided by the cap or cover.